Wire Definition and 1000 Threads

Homework Statement x represents the distance between the wire and P. The wire has infinite length. What is the magnetic field created by the wire at P? Homework Equations B=μ0I/2πr The Attempt at a Solution I thought the the first part of the wire creates a field equals to μ0I/2πx (directed...

Homework Statement The following data concerning a constantan resistance wire is taken from a catalogue: ''Diameter/m = 5.6 x 10^-4, Resistance per meter = 1.947 ohms, Resistance per Kg = 913 ohms''. Use the data to determine the density of the constantan wire in kg m^-3. Homework Equations V=...

Homework Statement A long straight wire of radius a and resistance per unit length R carries a constant current I. Find the Poynting vector N = E × H at the surface of the wire and give a sketch showing the directions of the current, the electric field E, the magnetic field H, and N. Integrate...

Hi, My understanding of an electromagnet is that it is a material with low susceptibility and high permeability, i.e. the magnetic field is not permanent but in the application of a current then the material gets a large magnetic field. In the application of a current the spins of the electrons...

Homework Statement A stainless-steel wire is 0.1 mm in diameter and 1 m long. If the outside of the wire is held fixed at 20◦C, estimate the steady-state current passing through the wire when the stainless steel at the centre of the wire begins to melt.Homework EquationsThe Attempt at a...

Homework Statement I plan on wiring an emergency flashlight to power an led. It must be able to store charge without batteries, generate charge and create a light. Homework Equations None, at least for now The Attempt at a Solution I was planning on following this diagram and modifying it to...

Homework Statement The circuit shown is in a uniform magnetic field that is into the page. The total current in the circuit is 0.20 A, flowing counterclockwise. At what rate is the magnitude of the magnetic field changing? Is it increasing or decreasing? Square wire loop with base and height...

Homework Statement Here is a link to the problem: https://imgur.com/a/0T9sF I am having trouble finding the time it takes the loop to leave the field in part a. Homework Equations ## emf=-\frac{d \Phi}{dt} ## ## \Sigma F=ma=mg-BIl ## ## \frac{dv}{dt}-\gamma v=g ## where ##...

I have a simple AC circuit. For example a battery with a capacitor. In the steady-state the capacitor has the same V of the battery. The wire that connect the two components is a very small cylindrical conductor, so it should have a surface charge distribution. It's that correct ? If no, why ?

What is the difference between the Magnetic Field Lines of the Dipole and Circular Current Carrying Wire at the centre?

Homework Statement A small but very powerful bar magnet falls from rest under gravity through the center of a horizontal ring of conducting wire, as shown in the figure below (on the left). The speed-versus-time graph, in arbitrary units, of the magnet will correspond most closely to which of...

I’ve looked at the answers given to the previous times this question has been asked, but I still don’t seem to understand how this holds in the case of a closed circuit. Here’s an explanation given before: “Think of the wire as a horizontal cylinder. If you apply an electric field pointing to...

Hello all, I've been pondering a problem with a current carrying wire in a magnetic field. The Lorentz force is easy, ILB, with a velocity 90 degrees to the B field. So let the force accelerate the wire. Assume only one segment of the wire that has current in one direction, say up, is in the...

Homework Statement A square loop, side a, resistance R, lies a distance s from an infinite straight wire that carries current I (pointing to the right). Now someone cuts the wire, so I drops to zero. In what direction does the induced current in the square loop flow, and what total charge...

Someone asked if it was possible to conduct electricity through a wire with a plasma. I ran across a article about a inventor who wanted to turn a antenna on and off very quickly. He said it was possible to do this by using a florescent light bulb as a element in the antenna. When a...

Homework Statement A semi-circular wire containing a total charge Q which is uniformly distribute over the wire in the x-y plane. the semi-circle has a radius a and the origin is the center of the circle. Now I want to calculate the electric field at a point located on at distance h on the...

Homework Statement I have a solenoid with a wire carrying current in the center. The wire has a radius of a, the solenoid has a radius of b. I need to find the magnetic field inside of each region. Inside of the wire, mu =/= muo. Homework Equations Wire B field = uo I/2*pi*r Solenoid B field...

Homework Statement Homework Equations The right hand curl rule gave me the counterclockwise direction for the magnetic field but I am confused about how is it going to work for the particle. Thanks The Attempt at a Solution

Homework Statement Hello. I have this problem: I have a ring which is sliding along a wire in the shape of a spiral because of gravity. Spiral (helix) is given as the intersection of two surfaces: x = a*cos(kz), y = a*sin(kz). The gravity field has the z axis direction. I have to find motion...

Homework Statement A wire 1.0 mm in diameter carries 5.0 A distributed uniformly over its cross section. a) Find the field strength 0.10 mm from its axis. b) Find the field strength at the wire’s surface Homework EquationsThe Attempt at a Solution I've used the Biot-Savart Law for a wire for...

Hi, I need to calculate the current in a 400nm piece of graphene. Can some one help me please? I found online that graphene has electron mobility of 200,000 cm^2/( V s). My best attempt is as follows. Using the equation vd = uE where E is the magnitude of the electric field applied to a...

A friend mine of gave me a problem : Calculate the Emf b/w the axis and surface of a long current carrying wire of radius ##r## and current density ##J##. I am not able to understand why there would be a potential difference between the axis and surface but i think that either of these could...

Homework Statement A telephone wire of mass m is strung between two poles, making an angle θ with the horizontal at each end find the tension at the center. in terms of Theta Mass and G The attempt at a solution i assumed it was T= mg/2sintheta using the same logic as the tight rope walker...

Hi! So when this system gets heated, how does the wire expand if it is bent like that? Would it expand horizontally or vertically? Also, when calculating the stress for the wire, I know that I use the thermal expansion equation for dL of steel, but other people said that you have to also...

<mod: moved from intro> Hello all! This is my first post in this forum. I am struggling with the following question regarding a hair dryer. The hairdryer can be seen as a cilinder with a fan inside blowing air at speeds from the table below and 1 nichrome wire which heats up consuming different...

I am trying to formulate the Current Density for a Loop of wire with a diameter,d, current,I, and an cross-sectional Area of the wire ##\pi(d/2)^2##. With spherical coordinates (radial, azimuthal, polar) ##\bar j## = ##\frac{I}{\pi(d/2)^2}*cos \theta *sin \phi \hat x##...

Homework Statement 0.5 kg bird lands on wire of telephone poles that are 50m apart. The wire sags 0.15m. What's the tension in the wire? Ignore weight of the wire Homework EquationsThe Attempt at a Solution I figured out the angle that would be created (0.34 degrees) when the bird lands and...

Why are they circular? You know, like this: Why not straight toward the wire?

Why is the red (power: pin 2) wire for the servo motor not connected to anything in this circuit? https://github.com/samyk/combobreaker/blob/master/Eagle Files/ComboBreaker_top.pngAlso, on the "bottom" schematic, the ground is connected to the feedback (potentiometer wiper) line...

I had learned from a book in a lower class that electric power distribution from the generating station is done in phases. Like in India, we have three phases of power transmission: the red, green and yellow colours distinguish the three phases. I believe the same is the case in any other...

Homework Statement Homework Equations R= pl/A effective resistance= 1/R The Attempt at a Solution I'm honestly don't know where to start, althought I know i need to do something with the 200 coils first, but I have no idea what should be done with it

Homework Statement Find the electric field of an infinitely long straight wire of charge ## \lambda## C/m at a point ##r= ix+jy## Homework Equations ##\int E.da = \frac {Q}{\epsilon_0}## ##E= \frac{\int dq}{4\pi\epsilon_0 r^2} ##r The Attempt at a Solution Drawing a cylindrical gaussian...

Greetings Denizens!, I'm building a small "zapper" for the purpose of keeping critters away from a deer feeder. Other than volts and amps ratings, I believe it is, for all intents and purposes an electric fence, just in a unique configuration (shape, not electrical specs - those are within the...

Homework Statement Homework EquationsThe Attempt at a Solution Right hand rule: magnetic field of P on Q is out of the page, and magnetic field of R on Q is also out of the page. Left hand rule: Force of P on Q is to the left and R on Q is to the right? Please help~ I know this is soooo...

Homework Statement A bead slides without friction on a horizontal rigid wire rotating at constant angular speed ω. The problem is to find the force exerted on the bead by the wire. Neglect gravity. Homework EquationsThe Attempt at a Solution The physical force acting on the bead is the force...

2 sets of 6x LED strips, each 12v 8.1a 97.2W, powered by a single cv 240W PSU, in parallel. The 2 sets are split at the PSU end, each set getting 120W separately. Schematic below, What I don't know is what gauge wire to use at points A and B? Can you please explain what should be used and why...

I need help with this problem. This is not a homework assignment, so please don’t send it over to the homework forum. It involves mechanical engineering dynamics that probably are more subtle and advanced then first year mechanical engineering dynamics. It might involve tensor analysis...

Homework Statement A conducting rectangular solid of dimensions dx=5m dy=3m dz=2m moves at a constant velocity through a uniform magnetic field B=(30mT)j. What are the resulting a)electric field within the solid,in unit vector notation? b)potential difference across the solid? Homework...

Homework Statement A metal strip 8.5cm long,0.65 cm wide,0.76 mm thick moves with constant velocity v through a uniform magnetic field B=0.2mT directed perpendicular to the strip,as shown in figure.A potential difference of 3.9 microV is measured between points x and y across the...

Homework Statement A bar magnet is attached to the end of a non-magnetic spring, with spring constant 484−1, as shown in the diagram. The other end of the spring is attached to a fixed force sensor which was zeroed when the magnet was at its equilibrium position, before being zeroed, the force...

A piece of wire is cut into two pieces. Denote the lengths of the two pieces by x and 12- x. Both pieces are then bent into squares. For which values of x will the combined areas of the squares exceed 5 cm^2? This question is from the quadratic inequality section of the textbook. I assume an...

Homework Statement Homework Equations I want to know whether my process is correct? THANKS! The Attempt at a Solution [/B] 1. By using Gauss's law: E\cdot 2\pi rz = \frac{\lambda z}{\epsilon_{0}}\Rightarrow E=\frac{\lambda}{2\pi\epsilon_{0} r} In my coordinate system...

Homework Statement Picture of the problem: I first need to calculate the magnetic field in point P caused by the piece of wire at z = R (so the top wire parallel to the y-axis). Homework Equations [/B] Biot-Savart law for magnetic fields: ##\vec {dB} = \frac {μ0*I} {4*π} * \frac {\vec {dl}...

Homework Statement Here is the problem. A small ball of mass m moves without friction attached to a cwire. The ball moves under the action of gravity and a spring of constant k whose other end is fixed in the point A, with OA = R / 2. The spring is tension free when the spring is R/2 to...

I want to wire some LED strips to the bass speakers in my car so that they will light up to the music. I reason that you can't wire the lights in parallel with the speaker because the lights can blow with too much volume. I also read that it will trash the sound quality. ? Anyway, my plan is to...

https://atarnotes.com/forum/index.php?topic=144870.msg953546#msg953546 http://i.imgur.com/XtCj6OP.png (worked solution on left and plain answer on right; they aren't the same and neither take into account the number of turns, which adds to the confusion) Is the book's answer correct? Doesn't...

Homework Statement The resistivity of a potentiometer wire is (40×10^-8) ohm-m and the area of cross section is (8×10^-6)m^2.If 0.2 amp current is flowing through the wire,then the potential gradient will be?? Homework Equations 1.Resistance=[(Resisitvity)×(Length)]/(Cross-sectional area)...

I am computing magnetic field around a thick conductor to do railgun force modeling. I am currently re-examining my magnetic field computation, and I have found some confusing results stemming from a fairly simple use of the Biot-Savart Law. The main issue is that the more nuanced application of...

Homework Statement A charged wire of negligible thickness has length 2L units and has a linear charge density λ. Consider the electric field E⃗ at the point P, a distance d above the midpoint of the wire. What is the magnitude E of the electric field at point P? Throughout this part, express...

I am trying to understand the magnetic dipole field via loop of wire. The above pictures show how this problem is typically setup and how the field lines are typically shown. The math is messy but every textbook yields the following: β = ∇xA = (m / (4⋅π⋅R3)) ⋅ (2⋅cos(θ) r + sin(θ) θ) The...